Brake cylinder release valve



Aug. 25, 1953 W, F, KLElN 2,650,138

BRAKE CYLINDER RELEASE VALVE Filed July 5, 1951 2 sheets-sheet 1 A A@im@ I nventor Willian Frelerck Klein fak( `Q A www1 MVVV, r

(ttornegs Aug. 25, 1953 Filed July 5, 1951 w. F. KLEIN 2,650,138 BRAKECYLINDER RELEASE'VALVE 72 sheets-sneet 2 AUX.RES.

EMERRES.

BRAKE CYL- Snventor Will-iam Fredeick Klein attorneys of this typePatented Aug. 25, 1953 UNITED STATES PATENT OFFICEl 2,650,138 BRAKECYLINDER RELEASE VALVE William F.

Klein, Watertown, N. Y., assigner to The New York Air Brake Company, acorporation of New Jersey Application July 5, 1951, Serial N o.

6 Claims. (Cl. 303-68) 'I'he Working chambers are charged With pressureuid flowing through the brake cylinder be `operated to release thebrakes following any type of a brake application, i. e. a serviceapplication or an emergency application. In operating trains over longdown-hill grades, it is common practice to `retain a light applicationat taining valves Were set to maintain pressure in the 'brake cylinders.This objection to the valves may be overcome by modifying the Pickertvalve as shown be rectified only by release and reapplication of Whilethis situation seems a remote possibility,- the present inventionprovides a valve in which this possible objection is overcome.

The invention will be described as embodied in a release valve of thepressure motor which controls the release in its abnormal or brake tion.

The invention will be described having refrence to the accompanyingdrawings, in which:

form of the invention.

Fig, 2 is a detail plan View of the pilot Valve assembly.

present invention.

The invention has been illustrated and will be described AB brake Whichthroughout the With other types of brake control Valves and such use iscontemplated.

Referring iirst to Fig. 3, reference numeral H generally indicates an ABtype control valve. The control valve H comprises portion l2, portionI4.

emergency reservoir IB.

The brake cylinder connection the pipe bracket I9 extends from l2 to therelease valve mechahe brake cylinder 22 receiveslair from the connectioni9 through the valve 2|. Exhaust `flovv from the brake cylinder 22passes from the connection |9 through appropriate ports in the controlvalve to an exhaust line carrying the retaining valve 20.

Referring to Fig. '1, the body portion 23 of the release valve 2|encloses a chamber 24 which is in direct communicationV with an inletpassage 25 connected to the brake cylinder connection I9 and a chamber26 which is in direct communication through a passage 21 with a pipeleading to the brake cylinder 22. Mounted in chamber 24 is a spider .28.A gasket 29 is provided to prevent leakage around the periphery ofspider 28 into the chamber 26. A valve seat 3| is formed on the lowerlface of the spider 28.

A slack diaphragm 32 is clamped at its periphery between the upper faceof the spider 28 and the lower face of the cap 33 of the release valve.Leakage between the cap 33 and housing 23 is Vprevented by the gasket34. Provided in the lower portion ofthe body 23 is a bushing 35 havingat its upper edge a valve seat 36. A double beat poppet valve 31 isreciprocable between an upper abnormal position in which it seatsagainst AVthe valve seat 3| and a lower normal position in which itseats against the valve seat 36.

Chamber 26 is in communication with a chamjber 38 through the ports 39in a bushing 4|. A passage 42 extends upwardly from the chamber Y38 to aworking space 43 defined between the cap 33 and the slack diaphragm 32.is provided with a stem 44 which extends upwardlythrough an opening inthe center of the diaphragm 32. The inner periphery of the diaphragm 32is retained between a anged sleeve 45 which encircles the stem 44 and athreaded member 46. The member 46 also serves as a .spring seat for thecoil compression spring 41 the other end of which reacts against the cap33.

Attached to the lower end of the body 23 is a housing 48 which sustainsthe universally tiltable ported head 49 of the forked lever 5|. -Pressedinto the guide bushing 52 1n which ciprocable. The stem 53 is biaseddownward by a coil compression spring 54 reacting between the housing 23and spring seat 55 attached to the stem 53. When the lever is moved inany direction, the universally tiltable head 49 moves f the stem 53upwardly forcing the valve 31 to its upper position in which it seatsagainst the valve seat 3| which isolates the chamber 24 from the chamber26.

Y In the upper position of the valve, the diagonvalve 31 is placed incom- .munication with chamber 38 through the ports 39 and the annularrecess 56. Thus, the chamber 26 is vented to atmosphere through thechamber 38 and the ports provided in the universally tiltable head 49.At the same time the working space is vented to atmosphere -through thepassage 42 which is in communication withthe chamber 38. The valve 31 ismaintained in its uppermost position by the pressure in the chamber 24which reacts on the diaphragm 32 to overcome the downward bias of spring41.

The apparatus described above is entirely conventional and no claims aredirected to it apart from the particular improvement afforded by thepresent invention.

According to the present invention the passage 42 is provided with achoke 51 whereby the Yworking space 43 is vented to atmosphere at arestricted rate when the vent valve is opened spring 12 which reactsbetween ning position,

'mounted This retaining valve -pressures existing in the fluid irom'theauxiliary reservoir `by either of two limiting factors.

emergency reservoirv remains by manipulation of the lever 5|. A by-pass58 is aorded between the passage 25 and the working space 43. Flowthrough the by-pass 58 is controlled by a valve assembly 59. The valveassembly 59 comprises a flexible diaphragm 6| which is retained in arecess in the housing 23 by a valve seat member 62.

The upper surface of the valve seat member 62 is provided with a gasket63. The diaphragm and gasket 63 are clamped as an assembly between thehousing 23 and the cap 33. The valve seat member 62, as best seen inFig. 2, comprises an outer annular portion 64 which is provided withradial ports 65 whereby fluid pressure may be admitted from the annularrecess 66 to the generally U-shaped chamber 61 which embraces the valveseat 68, as shown in Fig. l.

Cap 33 is provided with a bore 69 in which is reciprocable a disc valve1| which is biased toward its closed position by a coil compression thedisk valve 1| and cap 33.V Clearance is provided between the bore 69 andvalve 1| so that chamber 61 are charged at the same pressure. Mounted onthe diaphragm 6| is a follower member 13. This follower 13 is providedwith a generally U-shaped projection 14 adapted to engage at least aportion of the outer periphery orf the disk valve 1|. The working space15 dened between the diaphragm 6| and housing 23 is connected by apassage 16 with a pilot pressure connection 11.

As shown in Figure 3 the pilot connection 11 extends between the releasevalve 2| and the emergency reservoir |8.

When the control valve is in its normal runthe brake pipe |5, theauxiliary reservoir |1 and the emergency reservoir |8 are charged to thesame pressure. With the control Yvalve in this position, therbrakecylinder |22 is in communication with the nection on which the retainingmay retain a chosen pressure in the brake cylinder from a previousapplication of the brakes. With the control valve in running positionthe diaphragm 6| will be subject to the unbalanced emergency reservoir|8 and in the brake cylinder connection I9. The disk valve 1| isunseated under this condition, whereby the by-pass 58 is open.

If a service V.application is made by operation of the engineers brakevalve, not shown, trolled reduction of the brake pipe pressure Yto achosen pressure will result. This reduction of the brake pipe pressurewill condition the service portion |3 of the control valve to admitpressure l1 to the brake The amount of pressure brake cylinder 22 iscontrolled When less than a full service application is made, theauxiliary reservoir pressure uid continues to flow to the brake cylinderuntil its pressure falls slightly below brake pipe pressure at whichtime the control portion assumes what is known in the art as service lapposition in which further flow to the brake cylinder is prevented.During a full service application of the brakes, the flow of pressurefluid continues until the pressures in the auxiliary reservoir and thebrake cylinder have equalized. DuringV a service application of thebrakes, the fully charged. This pressure is effective in the workingspace 15 to cylinder 22. admitted to the the bore 69 and differentialacross the diaphragm 32 sucient to overcome the bias of the 'l With anemergency application in eiTect, if the lever l is manipulated the valve31 will be raised from its .seat 36 as before. With the valve 31 in hasmoved to release position.

During the emergency release function the Iease but equalizes with therising brake pipe pressure. By causing the pressure in the brakecylinder connection I9 to maintain the valve 1| "five to openthe valve7l. tion moves to release positlon, the brake cylinder 'i anddissipation of the pressure in the connection i9 permits the valve 31 toreturn to normal position.

While the invention has been described in an embodiment in 1s intendedposition' in which flow between said connection vand said cylinder ispermitted and an abnormal .position in which it seals said connectionand vents said cylinder, said valve being maintained in said abnormalposition by actuation of -a normally inert pressure motor, said pressuremotor -comprising in combination a movable abutment connected to saidrelease valve and having on its opposite faces a first and a secondworking space; means biasing said abutment toward said vfirst workingspace, the first working space communicating with said connection; aby-pass between said working spaces; a pilot valve in said by-pass;yielding means urging said pilot valve closed; an expansible chambermotor normally effective to maintain said pilot valve open and ,having afirst working chamber in communication with said connection and a secondworking chamber; a pressure fluid supply communicating with said secondworking chamber, said `supply being functionally connected with saidcontrol valve so that the pressure in said supply is greater than thepressure in said connection except during an emergency application ofthe VVbrakes at which time the pressure in said supply is dissipated atleast in part, said expansible 4-chamber motor permitting said yieldingmeans to close said valves when the pressure in said supply isdissipated; and valve means operable to vent said second working space.

4. The combination defined in claim 3 in which said system includes anemergency reservoir and said emergency reservoir issaid supply.

5. In combination with a fluid pressure brake controlling system of thetype including a brake pipe, a control valve, a brake cylinder and areservoir, said reservoir being charged from said brake pipe and causedby operation of the control valve to supply pressure fluid to said brakecylinder, a self-restoring brake-releasing mecha- Vnism forinterposition between the brake cylinder connection of said brakecontrol valve and said brake cylinder, said mechanism comprising areleasing valve having a normal position in which it affordscommunication between said brake cylinder connection and said brakecylinder, and an abnormal position to which it may be shifted and inwhich it seals said connection and isolates said brake cylindertherefrom; a normally inert pressure motor effective when actuated tomaintain said valve in its abnormal position, said motor comprising amovable abutment having on opposite sides thereof a first and a secondworking space; a manually operated valve Whereby said second workingspace and said brake cylinder may be vented at a restricted rate toactuate said motor; means affording a by-pass connection between saidworking spaces, a pilot valve in' said by-pass connection effective whenopen to prevent actuation of said motor; yielding means urging saidpilot valve toward its Aclosed position; fluid pressure motor meanscomprising a movable member having on opposite faces thereof a first anda second Working chamber, said first working chamber being in open comanemergency application of the brakes, saidy motor means normallymaintaining said pilot valve open but ineffective to overcome the biasof said yielding means at least when the pressure in said supply andsaid connection are equal.

6. A self-restoring brake releasing mechanism of the type adapted forinterposition between the brake cylinder connection and the brake cyl-Vinder of a fluid pressure brake controlling system, said systemincluding at least a brake pipe,

-a control valve, an auxiliary reservoir, an emer- VAgency reservoir,said brake cylinder connection ,and said brake cylinder, said releasingmechanism comprising a housing having therein two working spaces, thefirst of said working spaces being in constant communication with saidconnection; a movable abutment separating said spaces; a double-beatpoppet valve shiftable between a normal and abnormal position, saidvalve being Vmaintained in said abnormal position by said abutment whenthe second of said working spaces is vented, means biasing said valvetoward normal position, said valve effective in normal position topermit flow between said connection and said cylinder and effective insaid abnormal position to isolate said connection and vvent saidcylinder and said second working space; means to restrict the rate ofventing flow from said second working space; manually operated means toshift said .valve from normal to abnormal position; means affording aflow connection between said rst working space and said second workingspace; a pilot valve effective to control flowthrough said flowconnection; yielding means biasing said pilot valve to closed position;lfluid pressuremotor means when actuated maintaining said pilot valveopen in opposition to the bias of said yielding means; said fluidpressure Amotor means including two working chambers ,separated from oneanother by a movable abutment, one of said chambers being incommunication with said brake cylinder connection and the other chamberbeing supplied with pressure i'iuid from said emergency reservoir, saidmotor means `being inert when the pressure in said emergency reservoirand said brake cylinder connection are equal.

WILLIAM F. KLEIN.

References Cited in Vthe file of this patent UNITED STATES PATENTS

